1. Field of the Invention
The present invention relates to a method of blocking and searching for a host in an IPv4 network and, more particularly, to a method of blocking and searching for a host in an IPv4 network using a Neighbor Discovery Protocol (NDP) in an IPv6 network environment.
2. Background of the Related Art
The exhaustion of IPv4 (that is, a 32-bit address system) is gradually being realized. According to information provided in the IPv6 portal (http://IPv6.vsix.net) of Korea Internet Security Agency, it is expected that IPv4 addresses will be dried up after about 791 days as of Jan. 20, 2009. Lots of companies and government offices which have known the exhaustion of the addresses are performing a task of switching the network from the IPv4 network to an IPv6 network. Accordingly, there is a tendency that a demand for IPv6 is gradually increasing.
Furthermore, in IPv6, the automatic setting of an IP address is supported. If an address is automatically assigned as described above, there is a need to check the IPs of all pieces of equipment and maintain pieces of relevant information from a viewpoint of the management of network resources.
Furthermore, since IP addresses are automatically set, there is a problem in that malicious users may access the major equipment of a network without any restriction. Accordingly, it is necessary to manage and block the users.